Re-suggesting.

Sale 1: Sold for a Mega Strike Taunt: Battin' a Thousand (24-30 keys. Taking 27) and 17 ref

http://backpack.tf/profiles/76561198152288799?time=1429340400 (April 18th)

http://backpack.tf/profiles/76561198152288799?time=1430118000 (April 27th)

Hist of ML Trilby: http://backpack.tf/item/2162592590

Hist of Mega Strike Battin' a Thousand: http://backpack.tf/item/3375896134

April 18: Keys were 16.66 ref

27*0.9 + 1.02 = ~25 keys

Sale 2: Sold for a Skill Gotten Gains Taunt: Results Are In (15-19. Taking 17)

http://backpack.tf/profiles/76561198094559788?time=1429254000 (April 17th)

http://backpack.tf/profiles/76561198094559788?time=1429340400 (April 18th)

Hist of SGG Results Are In: http://backpack.tf/item/3410390607

17*0.9 = ~15 keys

Sale 3: Sold for a Disco Beat Down Gridiron Guardian (9-11 keys. Taking 10)

http://backpack.tf/profiles/76561198136799715?time=1425628800 (March 6th)

http://backpack.tf/profiles/76561198136799715?time=1425715200 (March 7th)

Hist of DBD Gridiron Guardian: http://backpack.tf/item/2598141061

10*0.9 = ~9 keys

Supporting proof thanks to MegaGenta:

http://www.tf2outpost.com/item/440,3465097848,324,5 -> http://www.tf2outpost.com/item/440,3447997952,30004,5

Sold for MN Sensei (Outdated at 22)